Traditionally, there are two methods for aiming a small caliber weapon while the operator is in motion: instinctive aiming from the hip and holding the weapon at eye level whilst sighting the target parallel to the gun barrel. Both methods have their drawbacks: the first is extremely inaccurate whilst the second requires that the marksman remains stationary during the aiming process, during which time he is vulnerable to enemy fire. Even then, conventional weapon sights are not accurate enough and there exist several prior art proposals for improving their accuracy.
Some methods for improving conventional weapon sights include mounting a laser emitter on the weapon and using it as an aim-point designator in training and operational conditions. However, if the laser light is in the visible range, the marksman exposes himself, whilst if it is invisible, an interface is required to render the laser spot visible. The interface is usually constituted by a pair of night vision goggles having a narrow field of view. In such devices the marksman sees the spot on a screen superimposed on an image of the target area included in a narrow field of view. The main drawbacks of such prior art systems are that the view is two-dimensional and therefore lacks perspective and that, since the field of view is narrow, the weapon has to be aimed accurately within the target area in order to see the target and the spot together on the screen. Preferably, a weapon aiming device would permit the marksman to view the spot, superimposed on the scene, so that he will be able to aim and shoot without taking his eye off the target. Such comprehensive devices do not presently exist in the field.
Various approaches have been suggested for improved weapon aiming systems. U.S. Pat. No. 4,177,580 (Marshall et al.) discloses a target system which is responsive to and indicative of the hits and areas of near miss of laser light pulses shot from a laser weapon aimed at the target system by a marksman. In the system proposed by Marshall et al., pulling the trigger directs a pulse of laser light towards a target having an array of light sensitive cells thereon. The light sensitive cells are responsive to the laser light pulses for indicating to the marksman where he "hits" the target and data processing means are included for indicating to the marksman his accuracy relative to a bullseye.
Clearly, such a system is effective for improving a marksman's aim but is not amenable to operational use in the field.
U.S. Pat. No. 4,553,943 (Ahola et al.) also proposes a system directed to an optical method for shooting practice. Again, a beam of light is directed towards a target on squeezing the trigger and the target is provided with light-sensitive elements thereon for generating an electrical signal. In particular, the light-sensitive elements receive continuous information from the weapon subsequent to its firing, thereby permitting the movement of the weapon during aiming and discharge to be analyzed and for the results to be recorded.
U.S. Pat. No. 4,577,962 (de Guillenschmidt et al.) discloses a method and system for aiming and firing a weapon at a real target, there being associated with the weapon a laser radiation source and detector mounted in close proximity to the weapon. The system includes a laser source whose orientation can be adjusted independently of the weapon-pointing operation, thereby permitting continuous detection of the radiation by the detector upon reflection from the target. Means are provided for maintaining the beam automatically oriented on the target regardless of target displacement, thereby permitting the location of the target relative to the marksman to be determined by triangulation. Such a system is of particular application for ballistic projectiles and guided missiles but is not applicable to small caliber firearms.